Board builds may now inclulde both the PWM and I2C RGB LED
    To add the PWM RGB LED driver:The board must define
    BOARD_HAS_LED_PWM and include rgbled_pwm the moulde list.

    This change attempts to start the either rgbled driver, that
    may or may not be present. If it is not present the +e
    setting allows the start up to continue.

   Board builds may now inclulde both the PWM and I2C RGB LED
   To add the PWM RGB LED driver:The board must define
   BOARD_HAS_LED_PWM and include rgbled_pwm the moulde list.

   This change attempts to start the PWM rgbled driver, that
   may or may not be present. If it is not present the +e
   setting allows the start up to continue.

  Added RGBLED_PWM0_DEVICE_PATH path
  Renamed the main of the PWM rgbled driver to create a seperate command

* revise pitch transition start and actuator_out_1 in transition

* update with new matrix math library

if _ftp_on is true, message_buffer was created and read, but it was
actually never written to, so this is not needed. It can only ever be
written to if _forwarding_on is true.

And the maximum number of configured file descriptors.

Note that this is per group, not per thread, so that e.g. logger and
log_writer_file show the same number.

VDev::getDev() is used in px4_access, which is used in orb_exists. And if
the topic does not exist, it iterates over all 500 indexes, which is slow.
It was slow even if the topic existed, the map reduces runtime from linear
to logarithmic (there are around 80 items in the container).
This is only used on posix.

* Fixed memory leak (indicated by cppcheck) upstream

This allows to run a command / function once when being deactivated. This avoids having flight modes which are not active run unnecessary code all the time.

Adding files which enable a simulation with the autonomous underwater
vehicle (AUV) from the Technical University Hamburg-Harburg